The present invention relates generally to hydraulic systems, and more particularly to using a wattmeter in conjunction with a hydraulic pump unit to obtain electric power measurements for use by a controller to determine hydraulic fluid parameters.
Hydraulic systems such as hydraulic pump units are used in a wide range of applications. Fluid power supplies for hydraulic rams, hydraulically actuated valves and lift oil systems are a few examples in which hydraulic pump units are deployed. A typical hydraulic pump unit includes a motor driven pump that supplies pressurized hydraulic fluid from a tank to actuators via a control valve. Because a typical hydraulic pump unit can transmit high forces of highly pressurized hydraulic fluid it is difficult to obtain accurate flow rate readings. Without accurate flow rate readings, the ability for determining hydraulic fluid parameters and performing diagnostics on these hydraulic pump units is impaired.